When your doctor says, "I feel your pain," you may say to yourself, "Yeah, sure." But Dr. Joel Salinas, a neurologist and researcher at Harvard Medical School and Massachusetts General Hospital actually does feel his patients' pain.

"I have synesthesia, which is a sensory processing condition that means that, when I experience something with one of my senses, I involuntarily experience it through other senses, too," he wrote on reddit.com.

"One particular form of synesthesia I have is mirror-touch synesthesia, where I physically feel everything the people around me physically feel. For example, if I were to see someone touch your cheek I would simultaneously, involuntarily, and vividly experience the same sensation of being touched on my own cheek. If you get a slap on the wrist, I feel a slap on my wrist. If you have a needle placed in your arm, I feel the needle placed in my arm … and so on."

Between 1 and 2 percent of people experience mirror-touch synesthesia, and it can be more of a curse than a blessing to feel the physical and emotional feelings of those around you. And with Dr. Salinas, whose patients suffer from strokes, spinal cord injuries, and other painful and debilitating conditions, he subjects himself to their pain.

Salinas, who was born in Miami to political refugees from Nicaragua, knew at an early age he was different. He could feel his parents' exhaustion from their jobs in his own body, and he learned to avoid participating in sports because they over-stimulated him.

In school, he was the oddball. "I made irritating commentaries if I picked up on someone's emotions and tried to bring it up," he told Pacific Standard magazine. "It was really out of place."

But it gives him a unique perspective on his patients as a neurologist.

"While it’s a very natural part of my day-to-day life given that I’ve had it since I can remember, being a neurologist that works with patients on a daily basis and having mirror-touch synesthesia makes for an interesting experience," he wrote on reddit. "It certainly gives a whole new meaning to 'empathy.'"